Uncovering terra incognita: new insights into the evolution of Antarctica and constraints for ice sheet models

An understanding of the evolution of the Antarctic plate has contributed to incredible insights into the Earth-system as a whole, including supercontinent cycles in deep time, as well as global cryosphere, ocean and climate evolution. Antarctica contains some of the oldest known crust on Earth, built over billions of years, and the breakup of Gondwana shaped the modern continent, leading to the opening of the Tasman and Drake gateways, development of the Antarctic Circumpolar Current, paving the way for the Cenozoic modern ice sheet.

Today, the Antarctic plate continues to impart significant forcings on the ice sheet and ocean circulation, which are not well captured in models that seek to describe ice sheet behaviour and forecast ice mass discharge and sea level change. Antarctic geology also records past ice sheet changes that can inform on future scenarios in a warming world. Yet there is much to learn, as the Antarctic continent reveals less than 1% of its rugged subglacial topography and its submarine margins remain poorly explored.

Here we review recent progress in uncovering Antarctica – we focus on the Wilkes, Queen Mary and Wilhelm II regions of East Antarctica, that represent part of the Australian and Indian conjugate margins, where multiple datasets including seismic tomography, aerogeophysical data, and rock- and sediment-based geological analysis provide new insights into the tectonic evolution and geological architecture of the Antarctic plate. These datasets also provide opportunities to address solid Earth-cryosphere interactions, such as the magnitude and spatial variability of geothermal heat flux to the base of the ice sheet, and ice sheet extent during past glacial cycles, with the aim of reducing uncertainties in models of the past and future evolution of the Antarctic ice sheet.